feat(cms): add Track Browser foundation with mode toggle and CmsTrackGrid

- Extend ICmsTrackService.GetPagedAsync with album/genre filter params
- Add CmsTrackBrowserViewModel (DI-scoped) with lazy album/genre load
- Extract CmsTrackGrid: 9-column layout, waveform status, per-row generate,
  info tooltip, album/genre filter params, OnStatusLoaded callback
- Restructure TrackList: remove MudTabs, add three @page routes, mode toggle,
  Generate All Missing button; album/genre stubs for next wave

DeepDrftManager/Services/CmsTrackService.cs

@@ -154,6 +154,7 @@ public class CmsTrackService : ICmsTrackService
 
     public async Task<ResultContainer<PagedResult<TrackDto>>> GetPagedAsync(
         int page, int pageSize, string? sortColumn, bool sortDescending,
+        string? album = null, string? genre = null,
         CancellationToken ct = default)
     {
         var client = _httpClientFactory.CreateClient(ContentCmsClientName);
@@ -162,6 +163,14 @@ public class CmsTrackService : ICmsTrackService
         {
             query += $"&sortColumn={Uri.EscapeDataString(sortColumn)}";
         }
+        if (!string.IsNullOrWhiteSpace(album))
+        {
+            query += $"&album={Uri.EscapeDataString(album)}";
+        }
+        if (!string.IsNullOrWhiteSpace(genre))
+        {
+            query += $"&genre={Uri.EscapeDataString(genre)}";
+        }
 
         HttpResponseMessage response;
         try
@@ -542,7 +551,7 @@ public class CmsTrackService : ICmsTrackService
     {
         // Re-use the paged endpoint: a single-item page carries the full TotalCount, so no
         // dedicated count endpoint is needed.
-        var paged = await GetPagedAsync(page: 1, pageSize: 1, sortColumn: null, sortDescending: false, ct);
+        var paged = await GetPagedAsync(page: 1, pageSize: 1, sortColumn: null, sortDescending: false, ct: ct);
         if (!paged.Success || paged.Value is null)
         {
             var error = paged.Messages.FirstOrDefault()?.Message ?? "Failed to load track count.";